Slaying the Cable Monster: What You Need to Know About HDMI Cables

By
Will GreenwaldFeb. 15, 2019, 10:41 p.m.

TVs have come a long way in the last few years, and HDMI has been evolving to match. Here's what you should know about buying video cables for your TV, and why a cheap cable will provide the same performance as an expensive one.

We're solidly in the age of 4K, with 8K looming on the horizon (don't worry; it'll be a few more years before that becomes remotely worthwhile to most average viewers). Even budget TVs boast 3,840-by-2,160 resolutions, pushing four times the pixels of 1080p TVs. That doesn't even consider high dynamic range (HDR), which can process more information per pixel thanks to wider ranges of light and color. That's a lot of data to send from your media streamer, Blu-ray player, game console, or PC. You're going to need a cable for it.

HDMI is the established standard for sending both video and sound from a home entertainment device to a TV over one cable. It's the best way to hook up DVD, Blu-ray, and Ultra HD Blu-ray players; video game consoles; and streaming media devices. If you're hooking anything up to your TV that's less than a decade old, HDMI is the way to do it. If you don't already have an HDMI cable (and if your new device doesn't include one), or if you just want to rearrange your home theater setup and find yourself lacking the slack you need, you're going to have to buy a new one.

Shopping for HDMI cables should be a simple process, but a wealth of choices, a wide range of prices, and a handful of potential holes to trip into can make it seem confusing and difficult. You need the right cable for the job, and ideally you want to spend as little as possible for it. After all, it's just a cable. Right?

This is where we come in. Here's everything you should know about HDMI cables, including what the different types mean, what different brands are available, and how concerned you should be about getting the most out of your 4K HDR TV.

The Numbers Game: What HDMI 1.4, 2.0, and 2.1 Actually Mean

A lot of the news around HDMI in the last few years has focused on the different versions of the cable standard. These are the fundamental specifications all HDMI cables and devices have to follow, based on the features they support and defined by the HDMI Licensing Administrator and HDMI Forum. In a broad sense, they're very important. However, you can effectively ignore them.

Credit: HDMI Forum. Click to enlarge.

Basically, the HDMI 1.4 specification was released 10 years ago, and all HDMI cables are manucatured to at least that specification. HDMI 1.4 was developed to look forward to 4K and set certain criteria to enable support for it in the future (from 2009) by providing enough bandwidth for 4K video at up to 24 frames per second. It's since seen iterations and upgrades to HDMI 1.4a and HDMI 1.4b, but that's again ancient history in the video space.

The HDMI 2.0 specification was released in 2013, and revised into HDMI 2.0a in 2015 and then HDMI 2.0b in 2016. This specification increased the maximum bandwidth of HDMI cables from 10.2Gbps to 18Gbps. This further cemented 4K support with the ability to handle 4K video at 60 frames per second with all forms of high dynamic range (HDR), and laid the groundwork for 8K.

HDMI 2.1 launched in 2018, and is designed to support 8K and higher resolutions with a maximum bandwidth of 48Gbps. The HDMI 2.1 specification can handle 4K and 8K video at up to 120 frames per second, with room to spare. Don't go looking for HDMI 2.1 devices or cables yet; the difference between them and HDMI 2.0 don't even apply until you push into 8K (which no consumer displays or devices do at this point).

These specifications are all important for making sure media streamers and other devices can transmit and TVs can receive enough data to do what they need to do, but for the cables themselves they aren't all that directly significant. Yes, some HDMI cables might have been manufactured under 1.4 and some might have been manufactured under 2.0, but those aren't the key details to keep an eye out for when shopping for them. The most important thing to keep an eye on isn't the HDMI specification, but the speed rating.

Cable Types: The Speed Factor

HDMI 1.4 and 2.0 don't matter nearly as much as their speed ratings, also defined by the HDMI Forum and HDMI Licensing Administrator. Those specifications touch on speeds with their maximum bandwidths, but they don't specifically define every cable. That's why HDMI cables are grouped together under one of four speed categories: Standard, High Speed, Premium High Speed, and Ultra High Speed.

Each category has its own sub-categories based on additional features like an Ethernet channel built into the cable or a stronger signal for automotive use, but the main label you should worry about is whether your cable is Standard, High Speed, or Premium/Ultra High Speed (for consumer uses, the two are interchangeable).

Standard is the most basic, and slowest, HDMI cable you can get. It has a bandwidth of 4.95Gbps, which is enough to send a 1080p signal to your TV, but not much more than that. Standard HDMI cables are rare to find in stores, but if you find an unmarked cable in a bucket somewhere, or hooked up to a home theater system that hasn't been upgraded in five years, it might be Standard. These cannot support 4K video at all.

High Speed is over twice as fast as Standard, with a minimum bandwidth of 10.2Gbps. The vast majority of new HDMI cables you shop for will be High Speed or above, which means they can carry a 4K signal. The hitch is that the bandwidth will only support 4K24, or 4K video at 24 frames per second. That's fine if you want to watch movies on Ultra HD Blu-ray, but if you have streaming TV shows or gaming hardware that can push 4K at 30 or 60 frames per second, it won't be able to handle it. High Speed HDMI cables also support HDR and wide color gamuts.

Premium High Speed pushes the bandwidth up to 18Gbps, which will cover any consumer-level video source you deal with. Premium High Speed cables support 4K60, or 4K video at 60 frames per second, with the capacity for BT.2020 color space and 4:4:4 chroma sampling. Basically, they can handle any 4K video you throw at them. These are future-proof cables that will keep you running throughout the days of 4K, and can even support 8K and higher resolutions with certain frame rates and features. They also offer a level of consumer security that the lower speed cables don't; the HDMI Licensing Administrator inspects and certifies all Premium High Speed cables, issuing a QR code you will find somewhere on the packaging that lets you make sure that the cable is indeed what it should be, and not substandard or counterfeit.

Ultra High Speed is the most extreme home theater future-proofing. Ultra High Speed cables have up to 48Gbps bandwidth, allowing for uncompressed 8K video with all the trimmings. You will not find any consumer media player or TV that needs an Ultra High Speed cable yet. They're total overkill for anyone outside of a movie studio.

If you've been keeping count, that's no less than three different cable types with High Speed in the name, and a lot of cable companies don't really care about the other qualifiers when packaging them. If you want to be absolutely sure your cable can handle 4K60 video, look for one that has the Premium High Speed QR code on the packaging. It's the most official way to be sure without testing it yourself.

Otherwise, if you just see High Speed on the cable package, look for any associated numbers. Specifically, the bandwidth and video resolution. It should clearly say 18Gbps, and possibly 4K60 (or any variation with those numbers, like "4K@60Hz"), somewhere on the box, bag, or listing. If those numbers aren't there, you can probably watch 4K24 video, but that's about it. And if it doesn't say High Speed anywhere on the package, save it for your old DVD player.

Length Matters

HDMI cables are digital, so you aren't going to experience fuzziness or static if the signal gets weak. It might show some strange artifacts, but then it will simply cut out. Because of this, things like "signal fidelity" and the importance of gold-plated connectors are completely irrelevant when shopping for them. At least, to a point, and that point is between 25 and 75 feet.

All signals, digital and analog, degrade over long distances. How they degrade depends on the strength of the transmitter, the sensitivity of the receiver, and how much interference the carrier picks up between them. That last part is where the cables come in. The longer a cable you plan to run, the better insulated it needs to be. Even then, at some point it needs an active component to amplify or repeat the signal to get it all the way to its destination. As a general rule, that point is around 50 feet. You can get longer cables without active components, but they won't be able to handle the full 4K60 HDR signal.

If your components are three, six, or even 15 feet from each other, you should be good with regular cables. If you're running long cables between, say, a projector and a closet full of home theater components across the house, you'll want to make sure your cables are rated to handle it. For commercial and high-end home installations that use long runs, you should seriously consider an extender system that sends the signal over Ethernet for most of the distance, switching back to a shorter HDMI cable once you run the easier-to-manage Ethernet through your walls or ceiling.

What Do You Really Need?

On paper, if you have a 4K TV or plan on upgrading to one, you should get a Premium High Speed or equivalent cable. The HDMI Forum would likely recommend going with a certified Premium High Speed cable, with a QR code for security, but after looking at the variety of cable options out there we're not so sure.

Many "high speed" cables available claim to support 4K60 video, deep color, 4:4:4 sampling, and other features without claiming Premium High Speed status or certification. These cables all claim the same 18Gbps bandwidth of Premium High Speed cables as well. In fact, the vast majority of HDMI cables you buy new in stores will say they have these features and bandwidth; you'll have to hunt to find a 10.2Gbps or 4.95Gbps HDMI cable that hasn't been sitting in a drawer for years. They just don't all have the QR code on the package, and aren't certified by the HDMI Licensing Administrator and the HDMI Forum.

Packaging can be deceiving, but cable prices can also be inflated. To determine whether you should err on the side of caution or frugality, we decided to run our own tests, and the results were slightly surprising.

The Great Cable Test

We tested a dozen HDMI cables from various sources. Monoprice provided us with a range of its own HDMI cables, including a commercial-grade extra-long cable. We also tested an AmazonBasics HDMI cable, several unbranded cables also available from Amazon, and even a few unmarked cables we simply found in a bucket in our test lab.

To test these cables, we used each one to connect a Murideo SIX-G signal generator to a TV capable of displaying 4K and HDR 10 content. The Murideo can output test signals at a variety of resolutions, frame rates, and color depths, so we could confirm whether each cable could actually carry each type of signal. We displayed a full-color test pattern at 1080p60, 4K24 both with and without HDR, 4K60 both with and without HDR, and 4K60 with HDR and 4:4:4 uncompressed color sampling. While we used seven different signal types, we found no change in signal fidelity between non-HDR and HDR signals at different color depths and sampling rates for each resolution and frame rate combination. The chart here has been truncated to reflect that.

To our considerable surprise, every cable we tested worked with every test signal, with two exceptions. The Monoprice 75-foot Commercial Series Standard Speed HDMI Cable could carry a 4K24 signal both with and without HDR, but once we moved up to 4K60, the signal failed. The Zosi HDMI cable (a brand that primarily sells home security cameras) we ordered from Amazon, which specifically said on the product page it's only intended for up to 1080p, also eventually failed when we tried to send a 4K60 HDR signal with 4:4:4 color sampling through it. And even then, the cable managed to handle a 4K60 HDR signal with compressed colors well enough; it was only when we bumped up the color sampling that the screen flickered and blacked out. Those were the only failures from a pile of HDMI cables. Even the completely unknown, used, buried-in-a-bucket HDMI cables we tried could carry 4K60 HDR with 4:4:4 color sampling.

This means, if you have a 4K TV and don't plan on keeping your home theater components too far away from it, nearly any HDMI cable you buy new will work. In fact, some of the cables you already have lying around might work, though you should test that by making sure your Blu-ray player, media streamer, or game system is outputting at the highest possible resolution and displaying HDR when it can, through the cable. Premium certification is ultimately not necessary for the average consumer with a fairly standard home theater setup, and even cables from no-name vendors on Amazon will probably work, though that isn't a guarantee.

Ultimately, if you don't need a cable right now and can wait a few days for delivery, we recommend Monoprice for any and all HDMI cables you need. It offers six-feet HDMI cables for a few dollars each, even if you want to splurge on particularly fancy, colorful, heavy-duty, or ultra-thin cables. If you want to be absolutely certain about the cable quality, it also has certified Premium High Speed cables, complete with the QR code for security, topping out at less than $25 for 25 feet.

Monoprice also consistently offers the widest range of options for cable lengths and types. The basic Select Series High Speed cable, for example, has nine different lengths between 1.5 feet and 15 feet. Most HDMI cable options on Amazon have far fewer incremental length choices, and that flexibility is very useful if you know your home theater components are going to be very close together and you want to keep dangling cables to a minimum. The company also offers a lifetime warranty for all cables.

This doesn't mean you should sneer at cables from Amazon or Best Buy, or even most unknown brands you can order online. Amazon's AmazonBasics cables are slightly more expensive and Best Buy's Insignia and Rocketfish cables are significantly more expensive, but they're all still perfectly functional. And if you buy them new and pay attention to the packagin, cheap no-name HDMI cables will also probably work with any signal you throw at them.

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About the Author

Will Greenwald has been covering consumer technology for a decade, and has served on the editorial staffs of CNET.com, Sound & Vision, and Maximum PC. His work and analysis has been seen in GamePro, Tested.com, Geek.com, and several other publications. He currently covers consumer electronics in the PC Labs as the in-house home entertainment expert, reviewing TVs, media hubs, speakers, headphones, and gaming accessories. Will is also an ISF Level II-certified TV calibrator, which ensures the thoroughness and accuracy of all PCMag TV reviews. See Full Bio